The invention relates to a fuel pump for a fuel tank of a motor vehicle, with an impeller arranged rotatably in a casing, with at least two rings, arranged in the two end faces of the impeller and one surrounding the other concentrically, of guide blades which delimit blade chambers, blade chambers located opposite one another being connected to one another, and with part-annular channels, arranged in the casing and located opposite the guide blades, for the formation of conveying chambers, one surrounding the other concentrically, for the conveyance of fuel from an inlet duct to an outlet duct.
Such fuel pumps are often used for the conveyance of fuel from fuel tanks to internal combustion engines of present-day motor vehicles and are known from practice. In the known fuel pump, one of the conveying chambers of the known fuel pump leads to the outlet duct and the other of the conveying chambers leads to an outlet, via which, for example, a suction jet pump is supplied with fuel. For the present-day high-performance internal combustion engines, however, it is necessary for the conveying chamber leading to the outlet duct to have a very large cross section. This results in a very large axial overall height of the fuel pump. Since the fuel tanks of present-day motor vehicles usually have a very low and angled configuration, however, only fuel pumps with an especially low overall height can be used. In practice, this is remedied by employing a plurality of fuel pumps in the fuel tank. This, however, leads to a highly cost-intensive outlay in the fuel tank.
The problem on which the invention is based is to configure a fuel pump of the type initially mentioned in such a way that it has especially small axial dimensions and has as high a conveying volume as possible.